Question
We planted about two dozen Sorcerer Rose bushes two yeas and, except for one issue, they look great: the red color fades. It's almost as if the color is being bleached out.

Local sellers think the sun is causing the problem. According to the label on the plants, the plants prefer full sun, 6+ hours of direct.

None of the other varieties in our yard has this problem.

We live in central Utah at an altitude of about 4,800 feet. The roses in question are on the west side of the property with little shade, but our summers here are not very hot.

Thanks for your help!

Answer
welp
you didnt mention what you are feeding the plants
prob a trace mineral problem.
are the other roses ok?
if they are, do any of your neighbors have the same roses and what are those roses doing?
Try giving them a good balanced organic fertilizer.
other then that it could be reverting to its root stock.
Are you pruning out any root stock that grows from the bottom at base of plant?